1,065,530 research outputs found
q-Differential equations for q-classical polynomials and q-Jacobi-Stirling numbers
No full textWe introduce, characterise and provide a combinatorial interpretation for the so-called q-Jacobi–Stirling numbers.
This study is motivated by their key role in the (reciprocal) expansion of any power of a second order
q-differential operator having the q-classical polynomials as eigenfunctions in terms of other even order operators,
which we explicitly construct in this work. The results here obtained can be viewed as the q-version of
those given by Everitt et al. and by the first author, whilst the combinatorics of this new set of numbers is a
q-version of the Jacobi–Stirling numbers given by Gelineau and the second author
Tobin's Q and Financial Policy
No full textRecent research in macroeconomics has emphasized the importance of linking the financial and real sectors and the need for working with optimizing models. Tobin’s Q model of investment would appear to provide a framework that can satisfy these two criteria. In contrast to the original presentation of the Q model, the formal development has not recognized that the firm actively participates in a number of financial markets; in this broader context, we show that Q is likely to be an uninformative and possibly misleading signal for investment expenditures . We then endeavor to turn this negative theoretical result to positive advantage in resolving a number of empirical problems with Q models, but the modifications dictated by the theory receive little support from the data.
[Handwritten list of names by an unknown author #1]
No full textHandwritten note by an unknown author, listing various names
Regulation Q and the behavior of savings and small time deposits at commercial banks and thrift institutions
No full textAn abstract for this article is not availableBanks and banking ; Regulation Q: Prohibition Against Payment of Interest on Demand Deposits
Dr Dean Kenning is a Research Fellow in The School of Fine Art at Kingston University. He is also a writer and an artist, most recently writing about art education. We interviewed him at the Royal Festival Hall, London.
No full textInterview with Q-Arts on Professional Practice in Fine Ar
Q Fever: An Emerging Reality in Portugal
No full textQ fever is a zoonosis caused by Coxiella burnetii with worldwide distribution at the increasing expression in Europe and endemic in Portugal. It is transmitted by inhalation of aerosols containing spores, main reservoir being cattle, goats and sheep as by ingesting cottage cheese or unpasteurized milk. The majority of patients are asymptomatic; however, they may present with fever, atypical pneumonia, acute hepatitis, cutaneous manifestations and rarely with cardiac or neurological involvement. Although most cases are self-limited, focal persistent or chronic Q fever can manifest years after the onset, wherefore follow-up is essential. The clinical heterogeneity may be so variable that the disease is often diagnosed only if it has been systematically considered. It should be especially taken into account in the presence of risk factors as valvular or joint prostheses, immunocompromised patients, pregnant women and epidemiological setting. The authors present a rare case of Coxiella burnetii pneumonia with cutaneous and hepatic manifestations without any risk factor. This case aims to emphasize the importance of Q fever in the differential diagnosis of fever or atypical pneumonia, even in the absence of known risk factors. The diagnosis is often challenging for clinicians and it is necessary to maintain a high index of suspicion. In Europe and specifically in Portugal is mandatory to report the cases to establish the real impact of this disease.info:eu-repo/semantics/publishedVersio
Spin Representations of the q-Poincare Algebra
No full textIn der Quantenmechanik können freie Elementarteilchen durch irreduzible Darstellungen der Poincare-Algebra beschrieben werden. Im Rahmen der Darstellungtheorie der q-deformierten Poincaré-Algebra untersucht diese Arbeit den Spin von Teilchen auf einer nichtkommutativen Geometrie.
Zunaechst wird eine Uebersicht ueber die Konstruktion der q-Lorentz-Algebra gegeben. Ausgehend von q-Spinoren, wird die q-Lorentz-Gruppe und die zu ihr duale q-Lorentz-Algebra konstruiert. Dabei soll gezeigt werden, dass die q-Lorentz-Algebra weitgehend durch mathematische Konsistenzbedingungen festgelegt ist.
Anschliessend wird die Struktur der q-Lorentz-Algebra untersucht. Ihre Darstellungstheorie einschliesslich expliziter Formeln fuer die q-Clebsch-Gordan-Koeffzienten wird zusammengefasst. Nach einer allgemeinen Betrachtung von Tensor-Operatoren in Hopf-Algebren werden die Vektorgeneratoren der Quantenalgebra der Drehungen berechnet. Zwei weitere Formen der q-Lorentz-Algebra, die vektorielle oder RS-Form (Wess) und die Quantendoppel-Form (Woronowicz), werden vorgestellt. Ein Isomorphismus zwischen beiden Formen wird gefunden.
Die Darstellungstheorie der q-Lorentz-Algebra wird verwendet, um die Algebra des q-Minkowski-Raumes zu konstruieren. Vertauschungsregeln zwischen den Erzeugern der q-Minkowski-Algebra und den verschiedenen Formen der q-Lorentz-Algebra werden angegeben. Die Struktur der von Rotationen und Translationen erzeugten q-Euklidischen Algebra wird eingehend untersucht und dadurch ihr Zentrum bestimmt. Daraus können zunaechst die nullte Komponente und schliesslich alle Komponenten des q-Pauli-Lubanski-Vektor bestimmt werden. Mit dem q-Pauli-Lubanski-Vektor können die Algebren der Spin-Symmetrie, die kleinen Algebren, berechnet werden, sowohl fuer den massiven als auch den masselosen Fall.
Irreduzible Spin-Darstellungen der q-Poincaré-Algebra werden konstruiert. Zunaechst werden Darstellungen in einer physikalisch interpretierbaren Drehimpuls-Basis berechnet. Die Berechnungen werden dabei durch die Verwendung des q-Wigner-Eckart-Theorems stark vereinfacht. Anschliessend wird gezeigt, wie Darstellungen durch die Methode der Induktion gewonnen werden können. Ausgehend von einer darstellungstheoretischen Interpretation von Wellengleichungen werden schlielich freie q-relativistische Wellengleichungen bestimmt. Dazu werden zunächst allgemeine Betrachtungen zu q-Lorentz-Spinoren, konjugierten Spinoren und dem Verhaeltnis von q-Impulsen und q-Ableitungen auf den Spinor-Darstellungen angestellt. Als Beispiele werden die q-Dirac-Gleichung, die q-Weyl-Gleichungen und die q-Maxwell-Gleichungen eindeutig bestimmt
Mapping the Discipline of the Olympic Games An Author-Cocitation Analysis
No full textThe authors conducted an author cocitation analysis on prominent authors writing about the Olympics during the 1990s. Author cocitation is an established bibliometric technique that can be used to measure the relative similarities of topics written about by the cited authors. This enables a visual representation of the “intellectual space” of the discipline, in this case the Olympics, to be created for the period under review. So core and peripheral research areas are identified, along with their major contributors. The representation appears as a two-dimensional cluster-enhanced map. Subject expertise was then applied to the results to place labels on the generated clusters of authors and their topics
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